New Jersey County Map showing county seats, present boundaries and dates of formation<A HREF="http://www.njarchives.org/links/webcat/#t">Table of Counties</A> Table of CountiesBased on The Story of New Jersey's Civil Boundaries, 1606-1968 by John P. Snyder (Trenton, 1969).COUNTY DATE FORMED COUNTY SEAT HISTORICAL DATA Atlantic 1837 Mays Landing Formed from Gloucester County. Bergen 1683 Hackensack Original county in East Jersey; Passaic County set off, 1837; Hudson County set off, 1840. Burlington 1681 Mount Holly Original county in West Jersey--court established 1681; boundary set with Gloucester County, 1692; Hunterdon County set off, 1714; part of Mercer County formed from Burlington, 1838. Camden 1844 Camden Formed from Gloucester County. Cape May 1685 Cape May Court House Original county in West Jersey--court established 1685; boundaries set 1692 Cumberland 1748 Bridgeton Formed from Salem County. Essex 1683 Newark Original county in East Jersey; part of Passaic County formed from Essex, 1837; Union County set off, 1857. Gloucester 1686 Woodbury Original county in West Jersey--court established 1686; boundary set with Burlington County, 1692; Atlantic County set off, 1837; Camden County set off, 1844. Hudson 1840 Jersey City Formed from Bergen County. Hunterdon 1714 Flemington Formed from Burlington County; Morris County set off, 1739; part of Mercer County formed from Hunterdon, 1838. Mercer 1838 Trenton Formed from Burlington, Hunterdon, Middlesex and Somerset Counties. Middlesex 1683 New Brunswick Original county in East Jersey; Somerset County set off, 1688; part of Mercer County formed from Middlesex, 1838. Monmouth 1683 Freehold Original county in East Jersey; Ocean County set off, 1850. Morris 1739 Morristown Formed from Hunterdon County; Sussex County set off, 1753. Ocean 1850 Toms River Formed from Monmouth County. Passaic 1837 Paterson Formed from Bergen and Essex Counties. Salem 1681 Salem Original county in West Jersey--court established 1681; formed from Salem Tenth, 1694; Cumberland set off, 1748. Somerset 1688 Somerville Formed from Middlesex County. Sussex 1753 Newton Formed from Morris County; Warren County set off, 1824. Union 1857 Elizabeth Formed from Essex County. Warren 1824 Belvidere Formed from Sussex County